Telephone signaling-circuit



7 (No Model.)

G. H. BLISS.

TELEPHONE SIGNALING CIRCUIT. No. 259,285. Patented June 13,131 882 H.PETERS, mwmwznw Wa-IMngin u. a

GEORGE H. BLISS, OF PITTSFIELD, MASSACHUSETTS.

TELEPHONE SIGNALING-CIRCUIT.

SPECIFICATION forming part of Letters Patent No. 259,285, dated June 13,1882.

Application filed October 20, 1881.

To all whom it may concern:

Be it known that I, GEORGE H. BLIss, of Pittsfield, county of Berkshire,State of Massachusetts, have invented an Improvementin TelephoneSignaling-Circuits, of which the following description, in connectionwith the accompanying drawings, is a specification.

My invention relates to the means employed for signaling intelephone-exchange systems, and has for its object to simplify the saidmeans, and thus reduce both the first cost and cost of maintenance ofthe apparatus of the exchange.

The invention consists in the combination, with a series of subscriberscircuits passing through a switch-board to the ground, each beingprovided with the usual indicating-instruments or annunciator-drops, of'a battery having one pole connected with the ground and the otherprovided with a metallic conductor extended in branches to everysubscribers station in the exchange, the said branches being normallyopen at each station, but adapted to be connected there with thesubscribers line. By this arrangement, when one of the subscribers Wiresis connected with the said battery-wire a current is passed through theindicating-instrument, giving a signal at the central office. The samebattery may be employed for calling up the subscribers. In someinstances, where certain groups of subscribers are remote from the mainbody of subscribers connected with an exchange,a local battery may beemployed having one pole grounded and the other extended into all thestations of the said group.

Figure l is a diagram illustrating my invention, the battery-circuitbein g indicated by a heavier line than those employed to indicate thesubscribers circuit. Fig. 2 is a similar diagram, showing the apparatusat the subscribers station and central office needed to put thisinvention in practice.

The subscribers circuits 1, 2, 3, &c., each passing through one or moresubscribers stations, a, are connected with the usual switchboard, I),at the central office, each passing through an indicating-instrument, 0,(shown in Fig. 2,) to the ground. The said subscribers circuits are alsogrounded at the terminals remote from the central office in the usualmanner, to enable signals to be sent from the cen- (No model.)

tral office. A signaling-battery, B, at the central oflice has one poleconnected with the ground or common terminal of the subscriberscircuits, and the other pole connected with the wire d, which isramified so as to have a branch passing to each of the subscribersstations to, where it is normally open. At each subscribers station asuitable switch or key is employed, which may be of the form illustratedin Fig. 2, the subscribers wire 2, entering the station from the centralofice, being connected with a spring switch or key, 6, which normallyremains in contact with a stop, f, from which the circuit is continuedto the other stations on that circuit and ultimately grounded for thepurpose of enabling signals to be sent from the central office. Thebattery-wire d is connected at each office with an anvil'piece, g, forthe key 6, so that when the said -key is depressed that portion of thesubscribers wire 2 between it and the central office is connected withthe battery-wire and the circuit completed through theindicating-instrument c and battery B, as will be understood onreferring to Fig. 2, while at the same time that portion of thesubscribers line and the ground on the side away from the central officeis disconnected from the said central office.

The battery B may also be connected by a wire, it, with a strip of theswitch-board b, that can be connected by the central-office operatorwith any one of the subscribers circuits, and the current controlled bythe key t'to operate a signal on the said connected subscribers circuitin any usual manner.

Where a group of subscribers circuits are remote from the main body ofthose forming an exchange, as shown at A, Fig. 1, the said subscriberbeing upon the circuits 10 12, leading to the switch-board b, a localsignalingbattery, 13, may be employed, having one pole grounded and theother extended into all the subscribers stations of the said group. Inthis case, if one of the subscribers circuits,10 or 12, is connected atany station with the branch from the battery B and the ground at the endof the said circuit removed, the circuit of the battery B will becompleted from the ground over the said subscribers wires 10 or 12, andthrough the indicating-instruments c therein at the central office tothe ground, and thus operating the said indicating-instrument. In

this case the battery B will be employed for operating a signal from thecentral office to the stations on the subscribers circuits 10 12.

I do not broadly claim a battery at the central office having one poleconnected with the subscribers wires and adapted to have its circuitcompleted from the subscribers station through the centralofficeindicating-instrument;

1 claim 1. In an exchange system, a series of subscribers circuits allentering a common central oflice, and each passing through asignalinginstrument, and a battery having one pole normally connectedthrough the said signaling-instruments with the said subscribers wires,combined with a battery wire leading in branches from the other pole ofthe said battery into all the stations on the said subscribers circuits,and a device at each station for connecting the said subscribers wirewith the said branch entering the station, substantially as and for thepurpose described.

2. In an exchange system, a group of subscribers stations rem ote fromothers connected with the same central office, upon circuits enteringthe said otfice and passing through indicating-instruments to theground, in combination with a battery located in the said group, andhaving one pole grounded and the other extended by normally-openbranches into all the said stations, and means to connect the saidbranches at any station with the subscribers wire, substantially as andfor the purpose described.

In testimony whereofI have signed my name to this specification in thepresence of two subscribing witnesses.

GEORGE H. BLISS.

Witnesses:

JAMES HARDING, JOHN F. VAN DEUs'EN.

